Table 6 Correlation between PIK3CA mutation type and clinical variables, including pathological response to chemotherapy
From: PIK3CA-activating mutations and chemotherapy sensitivity in stage II–III breast cancer
Exon 9 mutation status | Exon 20 mutation status | ||||||
|---|---|---|---|---|---|---|---|
Wild-type (n = 117) | Mutation (n = 12) | P valuea | Wild-type (n = 117) | Mutation (n = 11) | P valuea | ||
Pathological complete response (pCR) versus residual disease (RD)b | RD | 95 (82.6%) | 10 (83.3%) | 0.656 | 95 (82.6%) | 8 (80.0%) | 0.689 |
pCR | 20 (17.4%) | 2 (16.7%) | 20 (17.4%) | 2 (20.0%) | |||
Unknown | 2 | - | - | 2 | 1 | - | |
Residual cancer burden | 0 | 20 (22.0%) | 2 (25.0%) | 0.524 (0.513c) | 20 (22.0%) | 2 (28.6%) | 0.243 (0.492c) |
I | 7 (7.7%) | 0 (0%) | 7 (7.7%) | 0 (0%) | |||
II | 37 (40.7%) | 5 (62.5%) | 37 (40.7%) | 5 (71.4%) | |||
III | 27 (29.7%) | 1 (12.5%) | 27 (29.7%) | 0 (0%) | |||
Unknown | 26 | 4 | 26 | 5 | |||
HER2 status | HER2- | 104 (88.9%) | 11 (91.7%) | 0.617 | 104 (88.9%) | 10 (90.9%) | 0.659 |
HER2+ | 13 (11.1%) | 1 (8.3%) | 13 (11.1%) | 1 (9.1%) | |||
Grade | Grade 1–2 | 46 (47.4%) | 4 (50.0%) | 0.561 | 46 (47.4%) | 6 (60.0%) | 0.112 |
Grade 3 | 51 (52.6%) | 4 (50.0%) | 51 (52.5%) | 4 (40.0%) | |||
Unknown | 20 | 4 | - | 20 | 1 | - | |
Nodal status | Negative | 29 (24.8%) | 8 (66.7%) | 0.023 | 29 (24.8%) | 4 (36.4%) | 0.761 |
Positive | 88 (75.2%) | 4 (33.3%) | 88 (75.2%) | 7 (64.6%) | |||
Tumor size | T0 | 1 (0.9%) | 1 (8.3%) | 0.322 | 1 (0.9%) | 0 (0%) | 0.854 |
T1 | 7 (6.0%) | 0 (0%) | 7 (6.0%) | 0 (0%) | |||
T2 | 50 (50.4%) | 6 (50.0%) | 59 (50.4%) | 6 (54.5%) | |||
T3 | 18 (15.4%) | 2 (16.7%) | 18 (15.4%) | 1 (9.1%) | |||
T4 | 32 (27.4%) | 3 (25.0%) | 32 (27.4%) | 4 (36.4%) | |||
Ethnicity | Asian | 2 (1.7%) | 0 (0%) | 0.544 | 2 (1.7%) | 1 (9.1%) | 0.290 |
Black | 11 (9.4%) | 0 (0%) | 11 (9.4%) | 2 (18.2%) | |||
Hispanic | 40 (34.2%) | 6 (50.0%) | 40 (34.2%) | 4 (36.4%) | |||
Caucasian | 64 (54.7%) | 6 (50.0%) | 64 (54.7%) | 4 (36.4%) | |||
Median age (minimum-maximum), years | 50 (28–73) | 53 (42–72) | 0.313 | 50 (28–73) | 50 (28–73) | 0.084 | |